<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<form action="/form">
    <input type="text" name="username">
    <input type="password" name="password">
    <button type="submit">提交</button>
</form>
<p th:text="${mes}"></p>
</body>
</html>